Animal studies by researchers at the University of Arkansas for Medical Sciences (UAMS) used an antibody-based drug to provide immediate protection against the chronic abuse of phencyclidine (PCP). The studies mark the first time that a long-acting treatment has been developed to block or reduce the psychoactive effects of PCP in drug addicts, according to UAMS scientist S. Michael Owens, Ph.D. In earlier studies, he used a smaller fragment of the antibody to treat drug overdose.
Owens presented his findings here today at the national meeting of the American Chemical Society, the world's largest scientific society.
Owens said his new technique uses monoclonal antibodies-identical copies of animal antibodies cloned and reproduced in the laboratory-to prevent or slow the entry of PCP into the brain, where it produces its pleasurable effects. The ability to create huge quantities of these antibodies makes it possible to administer a very large dose in a single injection. In the animal studies, just one injection curbed the effects of PCP for at least two weeks-a period equivalent to one to two months in humans, Owens said.
This fast-acting therapy could make a profound difference in the way PCP addicts are treated, enabling doctors to offer addicts an effective anti-addiction medication that works immediately. By contrast, antibody-based approaches to creating vaccines entail weeks of waiting before benefits appear, Owens said.
PCP triggers hallucinations, psychotic behavior, violence, and even self-destruction.
In a 1997 NIDA survey of high school seniors, more than two percent of the students said they had used PCP in the preceding 30 days. "Young people are attracted to PCP even though they know how dangerous it is, because it is inexpensive and because it produces euphoria, hallucinations and a feeling of superhuman strength," said Owens.